“Unlike other mass-mailing worms, Mydoom does not attempt to trick victims by promising nude pictures of celebrities or mimicking personal notes. Instead, one of its messages reads: “The message contains Unicode characters and has been sent as a binary attachment.”

“Because that sounds like a technical thing, people may be more apt to think it’s legitimate and click on it,” said Steve Trilling, senior director of research at the computer security company Symantec. … “